Step 8: Label bottle

Step 9: Use your dehydrated alcohol

Step 10: Addendum

You may find that your salted out Isopropyl leaves a salt residue when it is burned. In many applications like a pocket stove the salt residue will co...

Salting out is a process that can be used to dehydrate Isopropyl alcohol, i.e., separate it from water in an azeotropic solution. Dehydrated Isopropyl is useful as a fuel by itself and in helping to determine the right amount of catalyst to add when making bio-diesel fuel.

Removing water also increases the Isopropyl alcohol's ability to:

> melt ice off your frozen windshield> dissolve water in gasoline> burn cleaner when used as a standalone fuel> provide your pet with an invigorating rub after his next bath, which is curiously strong enough (dry enough) to dislodge stubborn ticks and fleas> serve as a powerful pet or human wound antiseptic> wash out those wax filled ears> save you big $$$ (dough, ka-ching, moola, etc.) think money*

(*99.9% Isopropyl Iso-Heet at auto stores runs around 18.25 cents per ounce. 99.9% Isopropyl made from salting out 50%-91% generic retail brand Isopropyl runs around 6.73 cents per ounce. That is a savings of over 63%. If you use it to dry your gasoline then be sure to remove the residual salt using the addendum method.)

What you need:

- bottle of 50% to 70% Isopropyl alcohol- a wide mouth glass jar and lid, or other leak and Isopropyl proof container- a pound of non-iodized table salt- a turkey baster with a reduced size nozzle- an empty bottle equal in size to the bottle of Isopropyl alcohol.

Chemist chiming in. I don't know if anyone else has stated this because there are too many comments for me to look through all of them, so apologies if this statement is redundant.

99.999% IPA is a WORSE disinfectant then 70% IPA. There is a reason why the IPA in the pharmacy is 70% IPA and 30% water and that is because the water actually improves the efficacy of the product as a disinfectant. Alcohols as disinfectants are most effective in the 60-90% range, above or below that and they become less efficient at denaturing the microbe's proteins.

Also, please note that while alcohols are broad disinfectants and can kill a lot of different bacteria and fungi as well as deactivating viruses, they aren't as effective as say bleach or peroxides for killing dormant cells or spores that are designed to weather harsh conditions. So if something needs to be 100% for sure clean (for example, surgical equipment or for people with compromised immune systems), it's best to use a harsher product.

That being said, IPA is an excellent, topically safe (i.e. it's safe to touch, not to drink) product that does a really good job at making surfaces microbe free for most conventional purposes. Also it evaporates away after using it, is less damaging to surfaces and doesn't leave behind a bleach smell. Score!

This is probably a rather ignorant question, but I'm assuming any sort of non-iodized salt would suffice? I have non-iodized sea salt, so I'm assuming this would work fine, but I wanted to make absolutely sure.

No, "Isopropyl Alcohol" is the working name for the chemical compound 2-propanol (C3H7OH) usually mixed with water to about a 70% purity. "Denatured alcohol" is the working name for ethanol (C2H5OH) that's got nasty additives in it. They add impurities to deter people from drinking it... but I guess some hobos will always go for the cut-price booze, even to their own poor health :)

Just gonna add... If you're having issues with salt residue in your isopropyl, you can limit the solubility of the Sodium Chloride by doping the isopropyl with sodium hydroxide prior to salting it.

This has the advantage of having a solvation effect with the salt and the base (Sodium Hydroxide competes with Sodium Chloride for solvation with the water because both have a sodium cation). Any residual hydroxide compound should burn clean.

The biggest downside is that you might begin to push your isopropyl to undergo a synthesis reaction, but due to it's shape that's not very likely (that is to say, it's stearically hindered, and thus, unlikely to undergo any synthesis reactions).

Does anyone know a good way (cheap, not too involved manual labor) to get the salt out of the alcohol? I'm using it in an antique alcohol lamp, one that has a longish chimney, and the salt comes up the wick in rather huge quantities. It's a pretty orange while it's burning, but after it completely burns there's a solid crust on the end of my wick and the flame goes out. I have to trim the wick and relight it about every 15 minutes. Salted out IPA (isopropyl alcohol) with the salt somehow gone would be perfect!

Nice instructions, I'll try adding more salt (had tried this previously with mixed results, but I didn't use nearly as much salt). One thing: BE CAREFUL if you decide to distill anhydrous IPA, let alone fuel, as hinted in the intro. If you are gonna do that, make sure you use a hot plate or other electric heat source, i.e no open flame. Probably don't even try it with gasoline, unless you want to read about yourself on the local news (as a ghost).

Isopropyl alcohol is definitely not something you want to drink. Not all alcohols get you drunk, as far as I know ethanol is the only one that does it without some pretty nasty side effects (although hangovers aren't too fun ;))

most alcohols actually cause blindness, and ethanol is really the only alcohol thats safe to drink (not that its that safe eh ;D ) most other alcohols cause blindness in really small quantities, and theyr all very lethal poisons.

Most likely reason why people say to not use iodized salt is because it has iodine which can either A) make I2 which is non polar and may mix with alcohol as apposed to the water or B) could make a iodo-*suffix* compound. Only speculation from a hobby chemist though.

Wouldnt silica gel work to remove the water? I found an experiment online that somehow used silica in a distillation column to remove the water. The water vapor is easil absorbed by the silica gel. Silica will retain up to 40% of its weight in water. Seems like a good idea to me. Otherwise I would research how its manufactured on a larger scale.

Seems to me the problems are: 1. You'd need 2.5x the weight of water in silica gel - that's a fair amount, and salt is easier to come by. 2. Is silica gel soluble in isopropyl alcohol? If so, it wouldn't work at all. 3. Does silica gel absorb isopropyl alcohol? If so, it wouldn't work at all. Seems to me table salt is the better solution (no pun intended).

You could use lime to do the same thing. When I was growing up, my dad taught me this trick. Take some ordinary dry wall and bake it in a toaster oven OUTSIDE. The paper on the outside may burn off. The lime left behind will be completely dried out. Take the lime and crush it into as fine of a powder as you can. Add it to your alcohol and mix thoroughly. Let it set over night and either re distill or use a sepratory funnel to get the end product. We had a farm that had a large above ground gas tank for refilling our tractor. It would accumulate water and had to be dried out.

Methyl and isopropal can be absorbed through the skin, if you use it a lot it can have bad effects on you, rub downs with alks should only be with ethyl. They tell you now never rub your kid down with it . When I was a kid everyone knew to use rubbing alks for fevers. No Mas muchacha

isopropal is lousey for alcohol stoves, methyl is great , but ethyl is best (more btu's. Since we can drink it it is heavily taxed. Denatured alks are mixtures and can have ethyle and methyl and other crap. The other crap will soot pans and in some cases stinks like heck. Go to the site for S-L-X denatured alcohol, the stuff varies. GO to Minibull Designs.com and look for Tinny's fuel comparasons, it explains much. This is a great article/instructable. You could if you had equipment, or really cold cold streak, do cryogenic distillation. Put a few gallons in a drum freeze it to -20 for say a few days then let it 'warm to -10 few hours, then refreeze to -20, do this a few cycles and ice crytals will form on out sideof alcohol column. Well it does with hard apple cider. But you need those frigid upstate NY death by cold winters. Farmers could leave casks of hard cider freeze then pop a hole in the center and drain off the liquer. Not worth the effort though. Buy heet or Air Brake Antifreeze, pure methyl spirits, 98%. If you are lucky enough you may find a speed shop that sells it by the gallon out of a drum, (bring clean jug/can) 4-8 bucks a gallon. Sadly I can't find one by me. I enjoyed this piece I will re read later on in the week.

I'd be interested if you used a beer-making specific gravity meter for alcohol, to measure the SG of the alcohol your produced. Is it closer to 90%? Is this method efficient? Thanks for a great instructable.

You are welcome and thanks for the compliment. Just as I was getting ready to build a hydrometer it dawned on me that all I really need to do is to measure volume and weight. I have a good postal scale and volume is also pretty easy to measure with just kitchen wear. All measurements so far confirm 99-100% Isopropyl.

Interesting process to know, but seems like a lot of work to get questionable purity IPA. I can currently get 99.99... technical grade isopropyl by the drum for roughly 7 cents an ounce(volume). Just find your local chemical company. They'll sometimes deliver at no extra charge too.

I'm guessing but most people would only use 99% Isopropyl for backpack fuel and purity can be asserted with a post-salting out distillation. If you camp every weekend this is no more than a 32 fl oz bottle of fuel per month. A 55 gallon drum contains 7040 fl oz which would last the every weekedn backpacker about 18.3 years and since the price of Isopropyl has increased by 50% in the last year buying a whole drum now might actually pay off down the road. No harm in posting the name of your supplier...